Punch press for forming sheet metal shells



Nov. "21, 1933.

Filed Nov. 2, 1931 2 Shets-Sheet 1 Jive/2%" Nov. 21, 1933. McCREARY1,935,854

PUNCH PRESS FOR FORMING SHEET METAL SHELLS Filed Nov. 2. 1931 2Sheets-Sheet 2 Patented Nov. 21, 1933 UNITED STATES PATENT OFFICE TheHegeler Zinc Company, Danville, 111., a corporation of Illinois LLS JUN2+1942 Application November 2, 1931. Serial No. 572,645

13 Claims.

This invention relates to punch presses designed and adapted for formingor drawing sheet metal shells, comprising a plurality of sets or seriesof co-operating dies andpunches adapted 5 for simultaneous operation andarranged to act in succession on blanks delivered thereto, toprogressively draw or deform the same from the initial blanks to thefinished shells, whereby a completed shell will be produced at eachstamping operation.

A principal object of the invention is to provide a punch press for thepurpose specified, in which the dies and punches are arranged inseparate sets, each operating on a separate blank in a different stageof deformation, all of the punches being operatively connected so as towork together, thereby producing a completed shell at each stamping orpunching operation.

A further object of the invention is to provide a machine for thepurpose specified, in which the work will always be visible and readilyaccessible, thus permitting the operator to detect and remove defectiveshells, or shells which may become jammed in the dies in the operationof the machine.

Still a further object of the invention is to provide a machine for thepurpose specified, in which the dies are so arranged that, after eachpunching operation, blanks in process may be delivered from one set ofdies and punches to the next succeeding set, and which, preferably,comprises transfer or feeding means for delivering blanks ..in processfrom each set of dies and punches to the next succeeding set.

Still a further object of the invention is to provide improved means forsupporting and simultaneously operating the punches.

To effect the objects thereof, a punch press embodying my invention andimprovements, to comprises the various features, combinations offeatures and details of construction hereinafter described and claimed.

In the accompanying drawings in which the invention is fullyillustrated,

Fig. 1 is a side view, partly in section, of what I now consider apreferably form of punch press embodying my invention and improvements.

Fig. 2 is a view substantially similar to Fig. 1, showing modifiedmeansfor supporting and actu- 50 atlng the punches, in operation; and

Fig. 3 is a fragmentary view of the blank transfer mechanismsubstantially from the position 3-3 of Fig. 1.

7 Describing the invention with reference to the 65 drawings andreferring particularly to Fig. 1, in

REFSSUED the first instance, in which I have shown. what I now considera preferably form of punch press embodying my invention andimprovements, A designates the frame of the machine as a whole, B thedie assembly as a whole, and C the punch assembly as a whole.

The frame A comprises posts or pillars 1, the lower ends of which restupon a suitable base or foundation, the line of which is indicated at 2.Said frame also comprises a box structure 3 connected to and whichrigidly connects the upper ends of said posts or pillars 1.

As shown, the die assembly B is supported on spaced members 4 which formpart of the machine frame, and comprises a plurality of separate dieunits b secured to the supporting members 4 in spaced relation to eachother and at successively lower levels, from the initial to the finaldie.

As shown, each of the die units b consists of a hollow die-block 5comprising a bottom plate 6, side plates 7 and a top or bolster plate 8,rigidly secured together to form a unitary structure and which,preferably, are cast integral with each other. The openings 9 in thedie-blocks 5 are proportioned to receive the stampings formed by saiddies, respectively, with sufficient clearance to permit said stampingsto move freely therein to provide for delivering said stampings to asucceeding die after each stamping operation.

The dies 10 are secured in recesses 11 formed in the bolster plates 8,with the top surfaces in or slightly below the planes of the topsurfaces-of the bolster plates 8, respectively, and to provide foraligning the dies with the punches and the punch assembly, presentlydescribed, the dieblocks are secured to the frame members 4 so as to beadjustable in all directions, simple means for this purpose consistingof clamping screws which have threaded engagement with holes formed inthe frame members 4 and which extend through holes formed in thedie-blocks 5, said holes being larger than the shanks of the screws sayone-eighth inch /8) As shown, the die-blocks 5 are supported in suchrelation to each other that the upper surfaces of the bottom plate ofone die-block and of the top or bolster plate of the adjacent succeedingdie-block will be in the same plane. Also, said die-blocks are made ofsuch length that the ends of adjacent die-blocks will abut against eachother, thus providing continuous supporting surfaces along which blanks,in process, discharged from one die may be delivered in operativeposition to the adjacent succeeding die, the position of the blanksrelative to the die openings, being defined by suitable stops arrangedto position the blanks concentric, as near as may be, with the dieopening.

As shown, the initial die 10 is a blanking die adapted for stampingblanks from a thin sheet of metal shown at 13, which may be fed endwisetransversely of said die assembly with a step-bystep motion during theintervals between successive punching or drawing operations. If desired,however, my invention contemplates equally forming the blanks as aseparate operation, and feeding them to the machine either by hand or bymechanical means provided for the purpose.

The dies 10 are provided, respectively, with holes or openings ofsuccessively smaller diameters, the variation in the size thereofdepending upon the number of drawing or deforming operations to whichthe blanks are subjected, the size of the final die opening conformingto the contemplated outside diameter of the finished article.

As shown, also, the punch assembly C is mounted above and inco-operating relation to the die assembly B and comprises a fixed guideframe 14, mounted in bearings in which are plungers 15 secured to thelower ends of which are punches 16, each of said punches, excepting theblanking punch being sufliciently smaller than its die opening toprovide clearance between said punches and their respective die openingsto subject the blanks operated upon thereby to contemplated drawingaction, which will operate, in a usual manner, to elongate said blanksand reduce their outside diameters.

In operation, reciprocating movement is adapted to be imparted to theplungers 15 by means of suitable connection between their upper ends anda member 17 pivoted at 18 to the frame of the machine, the connectionbetween said plungers and the member 17 comprising links 19 pivoted tothe member 17 by means of rods 20, said links being connected to saidplungers by means of ball and socket joints 21 which, as shown, areformed at the lower ends of rods 22 adjustably secured to the links 19by clamps 23 formed at the lower ends of said rods or links, as shown.The ball joint connections will operate, in an obvious manner, torelieve the plungers 15 from all tendency to bind in their bearings, dueto the pivotal movementof the member 17.

In operation, oscillation is imparted to the member 17 by a pitman rod24 which pivotally connects a pin 25 secured therein with a crank shaft26 rotatably mounted in journal boxes secured to the top of the boxmember 3 of the machine frame and adapted to be driven by a belt, notshown, applied to a pulley 2'7 on said shaft.

Due to the fact that the blanks in process are elongated by eachsuccessive punching or drawing operations, it is obvious that the axialdrawing movement of the different punches will increase progressivelyfrom the initial to the final punch, and a particular advantage of theconstruction in which the punches are actuated by the pivoted member 17is that desired differential movement may be imparted to the differentpunches by connecting them to said pivoted member at different distancesfrom its pivoted end, corresponding to contemplated axial movementthereof, respectively, whereby each punch will be moved through arcs ofdifferent lengths corresponding to predetermined axial movement of saidpunches, respectively.

In the preferable construction shown, my improved punch press comprisesmeans for transferring the blanks in process from one die to theadjacent succeeding die, whereby the operation of the machine isrendered automatic so that it may run continuously.

As shown, said transfer means comprise push blocks 29, slidable in theopenings 9 in the die supporting block 5, said push blocks being securedto the ends of rods 30, the opposite ends of which are secured to anupright bar 31 pivoted at the ends of arms 32 formed on a frame member33 pivotally mounted between the ends of hubs or bosses 34 formed onbrackets 35 and 36 secured to the adjacent post or pillar 1 of themachine frame. In operation, oscillating movement is adapted to beimparted to the frame member 33, thereby imparting reciprocatingmovement to the rods 30 and the push blocks 29 by a cam 37 secured torotate with a shaft 38 rotatably mounted in brackets 39 secured to theadjacent frame post or pillar 1, rotation in operation being imparted tosaid cam shaft and cam by driving connection with the crank shaft 26consisting, as shown, of a shaft 40 rotatably mounted in bearing bosses41 on the machine frame, bevel gears 42 on which mesh with bevel gears43 secured to the crank shaft 26 and to the cam shaft 38, respectively.Formed in the surface of the cam 37 is a cam groove 44 which is engagedby a roller stud 45 mounted at the end of an arm on the frame member 33,the relation being such that rotation of said cam will impartoscillating movement to said member 33 and through it, reciprocatingmovement to the rods 30 and push blocks 29.

Instead of the punch assembly C shown in Fig. 1 and heretoforedescribed, I contemplate, as a modification of the invention, aconstruction in which the punch assembly comprises a crosshead mountedto reciprocate in bearings formed on the posts or pillars of the pressframe, to which reciprocating movement is imparted in operation bypitman rods, an end of each of which is pivoted to saidcross-head andtheir opposite ends to cranks on a crank shaft mounted to rotate inbearings in members of the machine frame, the plungers in which thepunches are secured, being rigidly attached to said cross-head and thelengths thereof being proportioned so as to impart contemplated movementto the punches in operation. 125

This modification is shown in Fig. 2 of the drawings and will now bedescribed. As regards features which are the same or substantially so,as corresponding parts of the press shown in Fig. 1, said parts aredesignated by the same reference characters in both figures and will bereadily understood from an inspection of the drawings without a separatedescription thereof in detail.

In the punch assembly C, 47 is the cross-head to which the punches 16are secured, the ends of said cross-head being slidably fitted tobearings 48 on the posts or pillars 1 of the press, and reciprocatingmovement is adapted to be imparted thereto by suitable connectionbetween said cross-head, and a shaft 49, consisting, as shown, of pitmanrods 50, the lower ends of which are pivotally connected to saidcross-head by pins 51 and formed in the upper ends of which are bearingsfitted to crank pins 52 on the crank shaft 49. The crank shaft is drivenfrom a suitable source of power by means of a belt, not shown, appliedto a driving pulley 53 secured to said crank shaft.

As shown, the thrust sustained by the crank shaft 49, due to theoperation of the punches 150 15, is absorbed by a segmental thrustbearing indicated at 54, secured to the frame member 3 which connectsthe upper ends of the'posts or pillars 1 of the frame of the machine, towhich the top side of the crank shaft is fitted.

Within the scope and contemplation of the invention, a punch pressembodying my invention and improvements may be equipped with usualaccessory devices, such as pressure blank holders maintained yieldingunder desired operating tension by compressedair or steel or rubberspring; or special stripping devices; or knockouts, which the characterof the work to be performed may require. Such devices are old and wellknown and can readily be supplied by mechanics skilled in the artwithout the exercise of invention and need not, therefore. be shown ordescribed in detail.

I claim:

' 1. ma punch press for subjecting sheet metal blanks to successivedrawing operations, the combination of a frame and correlated punch anddie assemblies mounted therein, the die assembly comprising a pluralityof separate, fixed dies, and means for supporting said dies in spacedrelation to each other and at successively lower levels from the initialto the final die, means defining passageways beneath said dies arrangedto receive blanks in process therefrom, respectively, proportioned topermit blanks delivered thereto to move freely therealong, the bottomsof said passageways forming continuous supporting surfaces along whichblanks are delivered from one die to the adjacent succeeding die, andthe relation being such that at each drawing operation the blanks willbe forced entirely through the dies to which they are successivelypresented.

2. The combination specified in claim 1, in which the die supportingmeans comprises plates provided in their top surfaces with recesses toreceive said dies with the top surfaces of said plates and dies flushwith each other.

3. The combination specified in claim 1, which comprises guide stopsarranged to position blanks in process relative to the different dies.

4. The combination specified in claim 1, in which the punch assemblycomprises plungers to which different punches are secured, means forsupporting and guiding said plungers, and means for simultaneouslyreciprocating the same.

5. The combination specified in claim 1, in which the punch assemblycomprises plungers to which different punches are secured, a fixedguide-framesupported on the machine frame provided with bearings inwhich said plungers are mounted to reciprocate, an actuating memberpivoted at one end to the machine frame, means flexibly connecting thepunch supporting plungers with said pivoted member at differentdistances from its pivot, and means for oscillating said member.

6. The combination specified in claim 1, in which the punch assemblycomprises plungers to which different punches are secured, a. fixedguide-frame supported on the machine frame provided with bearings inwhich said plungers reciprocate, an actuating member pivoted at one endto the machine frame, means flexibly connecting the punch supportingplungers with said pivoted member at different distances from its pivot,comprising links pivoted to said pivoted member, ball and socket jointsconnecting said links with said plungers, and means for oscillating saidmember.

7. In a punch press for subjecting sheet metal blanks to successivedrawing operations, I the combination of a frame, correlated punch anddie assemblies comprising a plurality of punches and dies supported onsaid frame in spaced relation to each other, respectively, the punchassembly comprising plungers to which different punches are secured, andmeans for simultaneously, imparting reciprocating strokes of differentlengths to said plungers and punches:

8. The combination specified in claim 7, in which the means forreciprocating said plungers and punches comprises a member pivoted tothe frame, means flexibly connecting said plungers to said pivotedmember at different distances from its pivot, and means for oscillatingsaid pivoted member.

9. The combination specified in claim 1, in

which the die supporting means comprises die blocks provided withpassageways proportioned to receive blanks in process from said dies,respectively, the top surfaces of said die blocks being provided withrecesses to receive said dies with the top surfaces of said dies and dieblocks flush with each other, and the bottoms of the passageways in saiddie blocks being flush with the top surfaces of adjacent succeeding dieblocks, respectively, providing a continuous supporting surface alongwhich blanks in process may be delivered from one die to the adjacentsucceeding die.

10. The combination specified in claim 1, which also comprises means fortransferring blanks in process from said dies, respectively, to the nextsucceeding die.

11. The combination specified in claim 1, which also comprises means fortransferring blanks in process from said dies, respectively, to theadjacent succeeding die, and stops for positioning said blanks relativeto the dies to which they are transferred.

12. The combination specified in claim 1, which also comprises pushmeans for transferring blanks in process from said dies, respectively,to the next succeeding die, and means for reciprocating the same.

13. The combination specified in claim 1, which also comprises means fortransferring blanks in process from said dies, respectively, totheadjacent succeeding die, comprising push blocks, an oscillatingframe, rods which connect said blocks with said frame, and means forimparting 05011? lating movement to said frame to reciprocate said rods.

m A. MCCREARY.

